شبیه سازی گردابه های بزرگ جریان خنک کاری لایه ای تک مجرا و مجموعه سوراخ خنک کاری

علوم کاربردی و محاسباتی در مکانیک

مقاله 5، دوره 35، شماره 1 - شماره پیاپی 31، اسفند 1401، صفحه 71-86   

نوع مقاله: مقاله پژوهشی

شناسه دیجیتال (DOI): 10.22067/jacsm.2022.78932.1140

نویسندگان

یاسر طاهری¹؛ مهران رجبی زرگرآبادی^{* 1}؛ مهدی جهرمی²

¹دانشکده مهندسی مکانیک، دانشگاه سمنان.

²دانشگاه صنعتی مالک اشتر

چکیده

در این مطالعه جریان خنک­کاری لایه­ای بر روی یک صفحه تخت به منظور بررسی اثرات به‌کارگیری مجموعه سوراخ بر اثربخشی خنک­کاری لایه­ای با استفاده از رهیافت RANS و LES شبیه­سازی شده است. هندسه­های مورد مطالعه شامل تک سوراخ استوانه­ای با قطر mm 1/11 و یک مجموعه سوراخ با 14 سوراخ استوانه­ای 97/2 میلی‌متری می­باشند، به طوری که سطح مقطع خروجی لوله خنک­کاری در هر دو حالت یکسان است. این مجموعه سوراخ به شکل ذوزنقه­ای چیدمان شده است. شبیه­سازی عددی در نسبت چگالی 6/1، نسبت طول به قطر 4، زاویه 35 درجه و نسبت دمش 25/1 صورت گرفته است. نتایج به دست آمده نشان می­دهند که جایگزینی یک تک سوراخ با مجموعه سوراخ شکل داده شده، منجر به افزایش قابل توجهی در اثربخشی خنک­کاری لایه­ای در هر دو جهت طولی و عرضی می­گردد، به طوری که افزایش در حدود 94 درصدی در میانگین سطحی اثربخشی خنک­کاری لایه­ای را در پی دارد. این افزایش در پی تغییر در ساختار گردابه­ها حاصل می­گردد. در مجموعه سوراخ خنک­کاری، مقیاس گردابه­های سنجاقی شکل کوچکتر از گردابه­های تک سوراخ است و شکل­گیری آنها در مکانی دورتر از سوراخ خنک­کاری صورت می­گیرد. در ساختار مجموعه سوراخ جفت گردابه­های anti-jet تشکیل می­شوند که جهت چرخش این گردابه­ها بر خلاف جهت CRVP است.

کلیدواژه‌ها

خنک‌کاری لایه‌ای؛ مجموعه سوراخ؛ شبیه‌سازی گردابه های بزرگ؛ ساختارهای منسجم

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